Blade mounting



April 24, 1962 J- P. HAAS BLADE MOUNTING 2 Sheets-Sheet 1 Filed Dec. 18,1958 INVENTOR. Jamzs EJ744615.

April 24, 1962 Filed Dec. 18, 1958 J. P. HAAS BLADE MOUNTING 2Sheets-Sheet 2 INVENTOR Jarmss H 766.

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"L9 rrozndlx' nite States This invention relates generally to rotarycut-off knives and more particularly to an apparatus for mounting bladeson rotating rolls of rotary cut-off knives.

Rotary cut-off knives are used in many industries to cut continuoussheets of material. For example, in the corrugated board industry, suchknives are used to cut continuous lengths of corrugated board intoblanks which may be printed, slotted and then folded into boxes. Onemachine for cutting such board is described in co-pending applicationSerial No. 55,987, now Patent No. 2,626,- 226 which is assigned to theassignee of this invention.

The rotary cut-off knives, as used heretofore, comprised twotangentially opposed axially spaced rolls each having attached to theperiphery of the roll a longitudinally extending knife blade which istapered lengthwise. Normally the lower roll carries a fixed knife bladewhich is not adjustable. The upper roll normally carries an adjustableblade which can be skewed angularly slightly from one end of the rollrelative to the other end. During or after the initial adjustment, theupper blade is clamped tightly. The rolls are rotated by a suitabledrive means, and the material to be cut in the form of long sheets isfed longitudinally between the rolls at the same surface speed as therolls. The knives meet across the material toshear the material by aslight scissors action every time the rolls make one revolution.

Adjustment of the cut-off blades is a critical and delicate operation.For example, the area of contact between blades, which causes theshearing of the material, travels from one end of the rolls to the otheras the rolls turn. This proper contact is obtained by skewing one of theblades slightly from one end of the rolls to the other. To obtain thisproper contact, the operator must check the quality of his adjustmentinitially by rotating the rolls and letting the blades shear a sheet ofpaper such as newspaper.

It is desirable that these cut-oif blades operate at high surfacespeeds. Also, it may be necessary to cut thick material such asdouble-walled corrugated board.

The apparatus used for adjusting and holding the knife blades heretoforehas been difiicult to manipulate, and has been unsatisfactory inmaintaining accuracy at high surface speeds or during the cutting ofheavy material.

This invention eliminates the aforesaid problems by providing a novellight-weight apparatus comprising a means including a pivot for easilyadjusting a blade adapted to pivot thereon and means for rigidly holdingthe adjustment of the blade.

The above and further novel features of the invention will appear morefully from the following detailed description when the same is read inconnection with the accompanying drawings. It is to be expresslyunderstood, however, that the drawings are not intended as a definitionof the invention but are for the purposes of illustration only.

FIG. 1 is a detail view partially in cross section of an embodiment of ablade and mounting therefor made according to this invention.

FIG. 2 is a partial isometric view of FIG. 1.

FIG. 3 is a partial elevation and cross section of a rotary cut-offknife having the embodiment of FIG. 1.

FIG. 4 is a schematic of a cut-off knife taken on line IVIV of FIG. 3showing the embodiment of FIG. 1.

Referring to FIG. 4, there is illustrated a cut-off machine 11 of thetype used to cut sheets of longitudinalatnt 1y moving material as in thepaper box making industry where corrugated board 13 may be fed tomachine 11 continuously from a special machine (not shown) called acorrugator. The boards travel at speeds in excess of 700 feet per minutebetween rolls 15 and 17 to which knives 19 and 21 are attached. In thiscase it is desirable that upper roll 15 and lower roll 17 of the cut-offknife be traveling at the same linear speed as the board when a cut ismade by knives 19 and 21 so that the cut is even. It is furtherdesirable that the outgoing strips of board fed from the corrugator at aconstant rate of speed are cut into lengths varying, for example, fromthirty inches to 180 inches. Conventionally, 36 inch diameter rolls areused and these rolls are accelerated and decelerated to control theangular speed of the rolls to bring the blades 19 and 21 to board speedfor shearing. Because of these factors a special drive means 23 shownschematically, is required. This may be a drive of the type disclosed inco-pending United States patent application Serial No. 55,978 as shownschematically in FIGS. 3 and 4. Drive 23 rotates rolls 15 and 17 throughshaft 24 and gear train 25 and rotates feed rolls 2.7 by means of asuitable shaft Whose speed of rotation is controlled by drive 23.Advantageously drive 23 is actuated through shaft 28 which is a commondrive with the corrugator so that the speed of the rolls 15 and 17 canfurther be controlled with relation to the speed of the board 13 androlls 27.

The lower knife blade 21 is illustrated in FIG. 4 as being fastened tolower roll 17 in the manner heretofore known. The positioning of thislower blade is fixed. As illustrated, socket head cap screws 30 arethreaded into shoulder 31 of plate 33 so that knife 21 is rigidly heldagainst shoulder 31 which runs longitudinally along the top of roll 17.Lower knife blade 21 cooperates with upper blade 19 as these bladesrotate to shear material fed therebetween.

Heretofore, the upper blade was attached to a roll and was mounted insubstantially the same way as the lower knife blade 21 except that theupper knife had a plurality of set screws threaded through the knifeblade body on either side of screws, like screws 30, into engagementwith a supporting plate like supporting plate 33. These set screws hadthe primary disadvantages that they were inadequate to adjust the upperblade as accurately as desired and were inadequate to hold theiradjustment once it was obtained.

In the embodiment of the invention, shown in FIGS. 1 and 2, thedisadvantages mentioned above are overcome. Upper blade 19 has an upperportion, generally designated 41, which has two tapered surfaces 43 and45 forming an edge 47. The lower portion, generally designated 49, ofthe blade extends on both sides of the upper portion so as to providetwo anchoring flanges 51 and 53. A plurality of holes 55 in theseflanges extend longitudinally in a line along the length of eachanchoring flange as shown in FIG. 2. In one embodiment of this inventionthese anchoring flanges 51 and 53 have formed therein a longitudinalrecess 71, which in cross section is substantially rectangular, toprovide two shoulders 73 and 75, shoulder 73 being thicker than theshoulder 75. Shoulder 73 is adapted to contact the side of a raisedportion of a plate 61 which forms a saddle 77. The bottom of recess 71rests on and is positioned by this saddle 77.

. Plate 61 is advantageously welded to the outside '79 of roll 15 asshown in FIG. 1. Shoulder 83 of plate 61 runs longitudinally in parallelrelation to the axis of roll 15 and has a plurality of threaded holes 85formed therethrough whose centers fall substantially on a line parallelto the face of the shoulder 83. Screws 87 thread into holes 85 so as tocontact spacer 91 which is interposed between shoulder 83 and anchoringsection 51. Advantageously these screws 87 have slots in one end whichare adapted to receive a screw driver for turning the screws and nuts 89are tightened on screws 87 against shoulder 83 to hold the screws in adesired position. Bolts 59 thread into a plurality of holes 93 in plate61 whose centers correspond to those of holes 55. The heads of thesebolts may be turned by a socket wrench so as to thread into holes 93.Lock washers 95 may be used to secure bolts 59 from loosening by beingsqueezed against the face of holes 55 in anchoring flanges 51 and 53.

In operation, knife blade 19 is placed on saddle 77, bolts 59 arescrewed into plate 61 clamping the blade against the saddle. Screws 87are then placed in holes 85 in three or four locations and screwedinwardly against spacer 91 to push the side of shoulder 73 against theface of saddle 77. Spacer 91 prevents marking of blade 19 by screws 87.By adjusting bolts 59 blade 19 pivots on saddle 77. This causes the tip47 of the blade to move forward or backward as desired and the desiredtwisting or skewing of the blade is thus obtained. After the blade isproperly positioned the remaining screws 87 are threaded against spacer91 and nuts 89 are tightened. After the proper adjustment and tighteningis made, the upper and lower rolls 15 and 17 are revolved so that knifeblades 19 and 21 shear board 13 fed therebetween by a slight scissorsaction that is induced by the meeting of the blades.

In an embodiment of this invention wherein the upper and lower knifeblades were 26 inches long, tests have shown that when one end of theupper blade was kept stationary at a reference position, the other endof this blade could be made to move .080 inch forward from the referenceposition, then .080 inch backward from the reference position. end ofthe blade tip was .160 inch. Furthermore, it was found that micrometeradjustments could be made and in operation these adjustments were heldeven when cutting material of relatively heavy gage were made at highsurface speeds.

The blade mounting of this invention as described above, is sturdierthan those heretofore and has the advantages that it is easy to makeaccurate blade adjustments. This invention can be used to greatadvantage with light weight rolls to cut heavy as well as light gagematerial at high as well as low surface speeds while maintainingaccuracy of adjustment.

What is claimed is:

1. Apparatus for adjustably retaining a longitudinally extending knifeblade body upon a support therefor, said knife blade body comprising alongitudinally extending portion having a cutting edge along the outerextremity thereof with first and second anchoring flanges projectinglaterally from opposite sides of said portion and extendinglongitudinally thereof, said retaining apparatus comprising a fulcrum onsaid support for engagement with the underside of said knife blade body,said fulcrum extending lengthwise of said knife blade body and beingofsuflicient height to permit pivoting of said knife blade bodythereover relative to said support, means for preventing lateralmovement of said knife blade body relative to said fulcrum, firstfastening means connecting said first anchoring flange to said supportto one side of said fulcrum, second fastening means connecting saidsecond anchoring flange to said support to the opposite side of saidfulcrum from said first fastening means, said first and second fasteningmeans being differentially adjustable and cooperating to pivot andsecure successive increments of said knife blade body relative to saidfulcrum whereby Thus the total travel of one said knife blade body isfixedly warped to accurately 10- onto and retain said cutting edge in askewed position relative to said support.

2. Apparatus for adjustably retaining a longitudinally extending knifeblade body upon a support therefor, said knife blade body comprising alongitudinally extending portion having a cutting edge along the outerextremity thereof with first and second anchoring flanges projectinglaterally from opposite sides of said portion and extendinglongitudinally thereof, said retaining apparatus comprising a fulcrum onsaid support for engagement with the underside of said knife blade body,said fulcrum extending lengthwise of said knife blade body and being ofsuflicient height to permit pivoting said knife blade body thereoverrelative to said support, means for preventing lateral movement of saidknife blade body relative to said fulcrum, a plurality of first screwsconnecting said first anchoring flange to said support at spacedintervals to one side of said fulcrum, a plurality of second screwsconnecting said second anchoring flange to said support at spacedintervals to the opposite side of said fulcrum from said plurality offirst screws, said first and second screws being differentiallyadjustable and cooperating to pivot and secure successive increments ofsaid knife blade body relative to said fulcrum whereby said knife bladebody is fixedly warped to accurately locate and retain said cutting edgein a skewed position relative to said support.

3. Apparatus for adjustably retaining a longitudinally extending knifeblade body upon a support therefor, said knife blade body comprising alongitudinally extending portion having a cutting edge along the outerextremity thereof with first and second anchoring flanges projectinglaterally from opposite sides of said portion and extendinglongitudinally thereof, said retaining apparatus comprising a fulcrum onsaid support for engagement with the underside of said knife blade body,said fulcrum extending lengthwise of said knife blade body and being ofsuflicient height to permit pivoting said knife blade thereover relativeto said support, a shoulder formed on the underside of said knife bladebody and extending longitudinally thereof, an abutment formed on saidsupport extending in the direction of said fulcrum, a plurality ofscrews threaded through said abutment along the length thereof andprojecting therefrom to force said shoulder against said fulcrum, firstfastening means connecting said first anchoring flange to said supportto one side of said fulcrum, second fastening means connecting saidsecond anchoring flange to said support to the opposite side of saidfulcrum from said first fastening means, said first and second fasteningmeans being differentially adjustable and cooperating to pivot andsecure successive increments of said knife blade body relative to saidfulcrum whereby said knife blade body is fixedly warped to accuratelylocate and retain said cutting edge in a skewed position relative tosaid support.

References Cited in the file of this patent UNITED STATES PATENTS391,949 Cottrell Oct. 30, 1888 2,067,767 Meisel Jan. 12, 1937 2,242,514DeSmith May 20, 1941 2,387,767 Nordquist Oct. 30, 1945 2,478,240Christman Aug. 9, 1949 2,551,335 Piazze May 1, 1951 2,632,510 DopplebMar. 24, 1953 2,658,574 Slettengrin Nov. 10, 1953 2,734,572 Pater Feb.14, 1956

